Coupling device



Dec. 26, 1933.

R. K. POTTER COUPLING DEVICE Filed Nov. l0. 1930 74 fia@ INVENTOR ATTORNEY llatentecvlv Dec. 26, 179.433 t 1,940,769--y o. A, 4 courLlNG rmvrcn.l y Ralph K. Potter, Landing, N. J., assignor to American Telephone and Telegraph Company, acorporation of New York f Y Applieation Novemberi, 1930 A o swamp. 494,793

esclaims. (cl. rvs-'44) yThis invention relates generally to. signaling systems. yMore particularly, ithis invention re-` lates to methods and means -forcouplingmtwo or more circuits which are capable of transmitting alternating currents. ThisV invention may alsobe applied'to arrangements for testing signaling or othersystems.- f

This invention'provides stable-arrangement,

for couplingitwo or more circuits. It embodies one or moremetallicdevices eachfof which has an aperture,y andV separates eachy pair of 4circuits `to be couplecLy Energy is suppliedi'rom onev of the circuits to the'adjacent circuit through the aperture located in the intermediate metallic device.; Afcoupling device of the typeforming the basisVv of this invention,` has been found to be useful especially because of its great stability. Y This invention will berbetter understood from the 1 detailed, description hereinafter, following, Vwhen read in connectonwith the accompanying drawing in which Figure l schematically repref sents the elements which may form the basis of this, invention; Fig. 2 shows a more detailed ar-r m rangementfofthe essential elements of the invention;.Figs. 3(a) and 3(2)) Ishow metallic de.-

vi'ces having apertures of `diierent sizes; Fig. v4L

showsA a multi-stage amplifier having: inductive elements coupledl through apertures; Figs. k5 and-r 6 disclose multi-stage ampliers having capacitive elements` coupled throughapertures; Fig. 7

shows a coupling arrangement employing anN aperture of variable proportions;` 'and Fig. 8- shows a coupling arrangement embodying two conductive surfaces which mayhave concentric apertures; u u. Y. l. The simple schematic arrangement of Fig. 1

embodies a couplingrdevice which has beensuc-v cessfully usedk gto a considerable Iextent inthe measurement ofrgainsv of receiving sets. A,The l Voscillator 1 which may be of any well known type,

is totally shieldedby a metallic containerr or case 3. The oscillator 1 ishcontrolled, by a knob 2k which may, for example, be mounted on the shaft of `a variable condenser forming part of the circuit of the ,-oscillator. The adjustmentof this x knob may be employed to change thefrequency of the'oscillator to any desiredvalue... `A coil designated 4 maybe part of the output circuit of the oscillator i or coupled thereto in any wel known manner. Y t. Y Y l A circular disc 5 of the ,cODpenorother confV ducting material, having'fan aperture, is placed opposite the coil4, and this `disc is held rmly in place by: ametallic ring capa-1A coil 'I Whichi maybe .part .of'any pick-up circuit and Amay, if

desired,` form part of ,a transmission or detector circuit, receives electrical .impression transmitted.

, theretoby the coil 4 through the aperture of the disc.` The voltage inducedv in coilA 'l by the .os-

cillator depends 'upon the size of the aperture of. 59

the disc 5.v Ituh'aslbeenfoundthat for round apertures-the voltages impressed uponcoil 7 vary Fig. 1.y f Here the metallic case 3 has av necked' Iportion 21 which `is externally threaded; fA

knurled knob `or ring cap 6 which may be made 75m of brass or other conducting material, is inter-v nally threaded in order to. conveniently mesh `with' the threaded neck 21. The disc 5 'which Q may, of course,. belformedof copperor other conducting material, hasyan aperturevof prede# 780 A terminedproportions and may be placed against the.end` of .the necked portion 2l of the case 3. The knobhas a shoulder which vsupports the disc 5 and holds the disc iirmly in position against the member 2l after the knob 6 is tightly screwed 85v againstthemember 21. It will be apparent that o any other disc; of.v different internal diameter maybe substituted for the :disc'f5 to provide a .l coupling aperture of any desired proportions;

t Figs.V 3(a and 3(b) show two 'circular discs `90 which may be used for coupling the oscillator of Fig. l :with the circuit connectedto the coil'7.` As suggestedl hereinabove; the relative outputs through two such apertures are definitely related toitheir sizes, and ifa large `measureable voltage.` 951 is' induced in the coil-7 of Fig. .1 by the use of alarge-aperture, as in Fig. 3(a)`, a much smaller voltage of known value` may then `be obtained forming, successive amp1i1iers.fThe'various unit ampliiiersjare designated 31, 32 and 33,:and yeach 105 may becomposed of` one or more suitably coupled Y vacuum tubes,.asis well known in the art. Thev shielding `metal1iccontainer or case 3 completely houses all ofthel ampliers and prevents leakage around `the apertures Vwhichwarefshown vin thel 11.0-

shielding metallic partitions 15 and 16. The coils coupled through the aperture provided by the partition 15 are designated 17 and 18, and those coupled through the aperture of the partition 16 5 are designated 19 and 20. The input lead of the first amplifier 31 is designated 1l, and the output of the last amplifier 33 may include the coil 12. The container or case 3 may be grounded, as shown, and moreover, if vacuum tubes form the w elements of the various ampliiiers, their iilamentsv may be connected to the container. Furthermore, the lower terminal of the coil 12 may be` similarly connected to the container. It will be obvious that all devices connected to the con- 15 tainer are grounded in common.

Any arrangement having an aperture which forms a common part of two or more circuits on either side of a shielding metallic partition may be employed to carry out the principles of this invention. There are, therefore, many methods of coupling circuits through an aperture aside from those shown in Figs. l and 4.

Fig. 5 shows an arrangement of capacity coupling through an aperture. The amplifiers 41 and 42 surrounded by the metallic shield 3 are coupled through an aperture formed in the partition 44. A` plate 45 is connected to the output circuit of the amplifier 41, and a similar plate 46 i'sconnected to the input circuit of the amplifier 36;. 42.y Plates 45 and 46 may be moved horizontally in order to change the coupling therebetween without requiring any modification in the size of the aperture. If the spacing of, thesev plates is increased, the coupling therebetween Will be v decreased, and conversely, as the spacing is de-L creased the coupling will be correspondingly increased. However, if the spacing of these plates is maintained constant, the coupling therebetween may be increased by increasing the size of 40y the aperture and decreased by correspondingly decreasing the size ofthe aperture.

Another arrangement employingV an aperture which is in common to two ycircuits is shown in Fig. 6. Here the circuits are designated 51 and 52, and they are shielded by the .metallic container 3. The eld generated across the aperture of the partition 44 produced, for example, by the flow of current along this partition between capacity plates and 55.', results in an 5ginduced voltage between the capacity plates 56 and 56 on the other side of the partition. The

plates 55` and55'` are connected or coupled to the circuit 51 and similarly, the plates56 and 56 are connected or coupled to the .circuit 52. It is 55 `to be especially noted that neitherV the plates 55 and, 56 forming one pair, nor the plates 55' and 56 forming the other pair, are located directly opposite the aperture provided in the par-V [55 size by any well known methods. Moreover, more than one aperture may be used to couple a pair of circuits. These, however, may be arranged adjacent to each other and, if desired, separated by small distances, or a single aperture may be arranged so that its position may be changed to .facilitate the balanceY of the voltage impressed.

upon a balanced circuit, as will be shown and described hereinafter in connection with Fig. '7.

In'Fig. 7 the reference character 61 may designate an oscillator for an amplifier or any other electrical circuit. The reference character 62 may designate an ampliiier or a modulator or any other device which may include, for instance, a pair of vacuum tubes arranged in push-pull relationship. The coil 65 may be part of the circuit 61 and the coil 66 may similarly be part of the circuit 62 and may, for example, be connected between the grid electrodes of any pair of tubes in push-pull relationship (two such tubes are shown by dotted lines). The midpoint of the coil 66 may be grounded between the filament electrodes of the two tubes.

The elements 64'and 64 forming the partition separating coils 65 and 66 are, of course, metallic and are adjustably mounted on the container or case 3. Each of the elements 64 and 64' may beslid back or forth between a pair of closely spaced metallic guides, and any change in the position of these elements will effect a corresponding change in the size of the aperture which may, for example, be rectangular in shape. The elements 64 and 64 may be held in any'pre'- determined positions either by friction or by suitable clamps or inY any other well known manner. The partitions 64 and 64 should be tightly fitted between the metallic guides so as to seal the container or case 3 as well as possible. It is to be noted that the aperture need not be located centrally within the container 3, and-the elements 64 and 64 may be moved into a position such that the aperture provided thereby will be closer to one side of the container than the other.

Fig. 8 shows another arrangement for coupling two circuits in order to control-the transfer of energy therebetween. T'he Winding '75 may be considered part of the circuit 71 which may be arranged, for example, as Aa source of oscillations. The winding 76 may be considered to be part of the circuit 72 which may, for example, be anyA amplifying, detecting or modulating circuit or, in fact, any testing circuit. Thev conductive shield 73 Ywill surround the circuit 71 including its winding 75 and the conductive shield 74 will surround the `circuit 72 including its winding '76. Both shields 73 and.'74 have apertures which may be concentric, as shown, but it will be understood that the center of one of the apertures may be displaced with respect to the center of the other aperture, within the scope of this invention.

While this invention has been shown and deg scribed` in certain particular arrangements mere- .ly for the purpose of illustration, it will be understood that the general principles of this invention may be applied to other and widely varied organizations without departing from thek spirit of the invention and the scope ofthe appended claims.

What is claimed is:

1. A coupling device for a pair oi alternating current circuits comprising a sheet of metal having a single aperture placed between said circuits for capacitatively coupling said circuits' solely through said aperture.

2. Alternating current coupling apparatus comprising a metallic surface having an laperture oi' variable area to control the amount of energy transmitted therethrough.

3.` Capacitative coupling apparatus for alternating current circuits comprising a metallic disc placed between said circuits, said disc havingar single circular aperture.

l4. Capacitative coupling apparatus for alter# nating current circuits comprising a disc of nonmagnetic material placed between said circuits, said disc having a single rectangular aperture.

`each other and an electrical shielding "surface interposed in said spacing, said surface having an aperture of controllable and predetermined dimensions for electrically coupling said` coils.

` 7. The combination of a metallic casing, twor electrical circuits within `said casing, anda con ductive partition spaced between said circuits, said conductive partition having an aperture of variable and controllable dimensions providing an air space for coupling said circuits. i

8. The combination of two circuits and a metallic device spaced from said circuits vand interposed therebetween, said device havingy an` aperture of variable and controllable dimensions providing an air space for coupling said circuits.

9. The combination ofv two circuits and `two coplanar metallic surfaces spaced from each other and located between fsaid circuits so as ,tol couple said circuits. j

10. Coupling apparatus for electrical circuits including ay metallic housing and aV pair of plates adjustably mounted at opposite sides of said housing, said plates being movable toward or away from each other in coplanar alignment and providing an air space. Y i 1 l1. The combination of a pair of metallic plates, two electrical circuits each including one of said plates, and a conductive surface surrounding and spaced between saidr plates,` said surface having an aperture providing an air space through which energy may be transferred. 1

l2. The combination of a pair of amplifiers eachy having a reactiveV element and a shielding surface of conductive material surrounding yandspaced between said reactive elements and having an aperture providing an air space for capacitatively coupling said elements. i

.13. The combination of two circuits, two plates l connected respectively to said circuits, anda shielding surface having an aperture located between said plates, said aperture providing an airV space for coupling said plates, said circuits being coupled solely through said aperture. y 14. The combination of a metallic `housing having a necked portion, a source of electrical energy within said housing, and a metallic disc `held against said necked portion andhaving an aperface having an aperture, which consists in changture providing an yairv space for the free flow of currents, n

15. Apparatus for the control of the 'transfer of electrical energy from a source of such energy comprising a shield surrounding said source, said yshield having an aperture of controllable and predetermined dimensions providing a non-conductive space through which energy may be transferred.

, 16. The combination of a `source of alternating -current energy, and a shield surrounding said source, said shield having an aperture which'is Y non-conductive and of controllable dimensions through which energy may be transferred.

rr1'1. The combination of a source of electrical energy, and means to control the flow of .energy from Said source,fsaid means comprising a conducting surface surrounding said source and having an aperture of controllable and predetermined dimensions providing a non-conductive space through which energymay be emitted.

18. The method of changing the flow of energy l n from a first circuitto a second circuit, the first circuit being surrounded by a conductive suring the size of the aperture.

19. The combination of two circuits, a metallic shield surrounding both circuits, a second me- `tallic shield separating oneof the circuits from the other. and having an aperture for the control of the capacitance between said circuits.

20. The combination of a source of electrical energy, a circuit external to said source, and an electrical shielding surface surrounding said circuit and having' an aperture providing an air space of adjustable dimensions for controlling the transfer of energy from said source to said circuit. n i

21. The combination of two circuits and a conductive surface housing both circuits and providing a separating partition, rthe separating partition of said conductivel surface having an aperture providing an air space for coupling both circuits. u n

22. The combination of a source of electrical energy, a circuit external to` said source, and two conductive surfaces shielding said source and said circuit respectively, each conductive surface having an aperture, both apertures being concentric and providing air-spaces for coupling saidisource and said circuit.

23. Coupling'apparatus'comprising two parallel conductive surfaces having concentricv apertures providing air spaces through` andbetween which alternating current energy may'freely flow. 130 i RALPH K. POTTER. 

